A notion occurred to me today for my detached garage-workshop conversion.
It would be useful to have a small sink with a cold water supply tucked away
in one corner, but I can't run a proper water feed to it from the incoming
main (or anywhere else in the house). As it would only be for occasional
and limited (and non-drinking) use, would it be practical to set up a
roof-level rainwater tank and take a supply from that? The tank could have
an overflow to the same water butt that's currently fed from the garage's
gutter. In dry spells it would be easy enough to top up the tank from a
hosepipe if necessary.

Obviously, the output from the tank would need to be filtered, and that's
where I see a possible snag. Wouldn't any filter get clogged rather
quickly? A filter in the tank would be pretty inaccessible, but perhaps
something cold be rigged up in the supply pipe? And perhaps a mesh covering
over the top of the tank would help?

Maybe this or something like it standard practice in these eco-conscious
days and I'm asking the obvious. Apologies if so, but any thoughts will be
very welcome. Thanks.

Bert

I've now had a quick look round at existing systems and as I suspected there
are some very sophisticated (and pricey) arrangements possible. What I'm
considering is something far more basic: no underground storage, no pumping,
no complex distribution, just a single cold-water feed directly down to a
small sink. If the filtering can be made to work on such a small scale, it
seems a feasible proposition.

Bert

On 08/08/2011 16:02, Bert Coules wrote:
A notion occurred to me today for my detached garage-workshop
conversion. It would be useful to have a small sink with a cold water
supply tucked away in one corner, but I can't run a proper water feed to
it from the incoming main (or anywhere else in the house). As it would
only be for occasional and limited (and non-drinking) use, would it be
practical to set up a roof-level rainwater tank and take a supply from
that? The tank could have an overflow to the same water butt that's
currently fed from the garage's gutter. In dry spells it would be easy
enough to top up the tank from a hosepipe if necessary.

Obviously, the output from the tank would need to be filtered, and
that's where I see a possible snag. Wouldn't any filter get clogged
rather quickly? A filter in the tank would be pretty inaccessible, but
perhaps something cold be rigged up in the supply pipe? And perhaps a
mesh covering over the top of the tank would help?

Maybe this or something like it standard practice in these eco-conscious
days and I'm asking the obvious. Apologies if so, but any thoughts will
be very welcome. Thanks.

Bert

You would need to drain and close it off in winter or keep it warm

In article ,
"Bert Coules" writes:
A notion occurred to me today for my detached garage-workshop conversion.
It would be useful to have a small sink with a cold water supply tucked away
in one corner, but I can't run a proper water feed to it from the incoming
main (or anywhere else in the house). As it would only be for occasional
and limited (and non-drinking) use, would it be practical to set up a
roof-level rainwater tank and take a supply from that? The tank could have
an overflow to the same water butt that's currently fed from the garage's
gutter. In dry spells it would be easy enough to top up the tank from a
hosepipe if necessary.

Obviously, the output from the tank would need to be filtered, and that's

I don't think so. I don't filter the water from my water butt, and
it always looks very clear. Muck either floats on the top, or sinks
to the bottom. Make sure your take-off is above the bottom. You might
also want to plumb in a separate bottom drain so you can easily flush
out the tank once in a while. I often have a bucket of water which
I've filled from the water butt, and I see the local cats and foxes
regularly drinking it, so it can't be too bad. I also run the pressure
washer from the butt for cleaning the car and other things, and that's
been going fine now for over 10 years.

where I see a possible snag. Wouldn't any filter get clogged rather
quickly? A filter in the tank would be pretty inaccessible, but perhaps
something cold be rigged up in the supply pipe? And perhaps a mesh covering
over the top of the tank would help?

Use a tank with close fitting lid, as normally used for cold water
storage, unless the want the place swarming with mosquitos. Might
want to arrange so the overflow skims off the surface muck (they
usually aren't arranged like this in header tanks).

You'll also want a tap which operates on very low pressure, and you
probably want to run the pipework in 22mm for as much of the way as
you can. That may also help prevent freezing, but you'll need to lag
the pipework, and the thicker the lagging, the longer a cold spell
it will survive. Don't forget the tank too, although that's just as
much to prevent excess heating in the summer.

I keep thinking about doing something like this for toilet flushing.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 08/08/2011 16:02, Bert Coules wrote:
A notion occurred to me today for my detached garage-workshop
conversion. It would be useful to have a small sink with a cold water
supply tucked away in one corner, but I can't run a proper water feed to
it from the incoming main (or anywhere else in the house). As it would
only be for occasional and limited (and non-drinking) use, would it be
practical to set up a roof-level rainwater tank and take a supply from
that? The tank could have an overflow to the same water butt that's
currently fed from the garage's gutter. In dry spells it would be easy
enough to top up the tank from a hosepipe if necessary.

Obviously, the output from the tank would need to be filtered, and
that's where I see a possible snag. Wouldn't any filter get clogged
rather quickly?

Look at Koi pond filtration systems for an idea of how to filter the
water. The most important, for your purposes, would probably be to have
a first stage vortex filter. A series of over and under baffles after
that should remove most, if not all, of the solid debris.

A filter in the tank would be pretty inaccessible, but
perhaps something cold be rigged up in the supply pipe? And perhaps a
mesh covering over the top of the tank would help?

Unless you like green water, the storage cistern should be light proof.
You would probably also want to keep insects out with a Byelaw 30 kit -
a screened air vent and an insect screen in the overflow pipe.

Maybe this or something like it standard practice in these eco-conscious
days and I'm asking the obvious. Apologies if so, but any thoughts will
be very welcome. Thanks.

Commercial water harvesting systems are available, but they tend to be a
bit pricey.

Colin Bignell

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Bert Coules"
saying something like:

Apologies if so, but any thoughts will be
very welcome. Thanks.

Occasionally I service a boiler in a church that has no mains water - it
being fed from a tank filled from the guttering.
I'm always bloody careful to disinfect my hands after washing them
there.

On Mon, 8 Aug 2011 16:11:24 +0000 (UTC),
(Andrew Gabriel) wrote:


Use a tank with close fitting lid, as normally used for cold water
storage, unless the want the place swarming with mosquitos. Might
want to arrange so the overflow skims off the surface muck (they
usually aren't arranged like this in header tanks).


In the tropics I had a house which used rainwater from the roof for
everything. A thin layer of kerosene/paraffin dealt with the mosquito
issue.


--
AnthonyL

Thanks to everyone for the replies and thoughts. I've done a bit of reading
round on this and it does seem to be a practical proposition, though my
initial idea of simply having a free-standing tank to catch direct rainwater
fall doesn't seem to be the popular way to go: most harvesting systems, even
small-scale ones, appear to work by collecting run-off from roofs.

I didn't know about the existence of low-pressure taps, so particular thanks
to Andrew for that bit of info.

I've also found this:
http://www.rainwaterharvesting.co.uk...filter-820.php - a
low-cost self-operating downpipe filter to get rid of leaves and other
debris - which might be useful.

Bert